I. Field of the Invention
The present invention relates generally to the field of accident investigation and analysis. More particularly, the present invention relates to drawing aids and templates that facilitate the accurate diagramming of accident scenes by police officers or other traffic investigators.
II. Description of the Prior Art
It is the usual procedure for investigating police officers to diagram traffic accident scenes in conjunction with routine investigations. During the investigation, a number of measurements are made, witnesses are interrogated, and sketches and notes are accumulated. Afterwards, when the officer leaves the field and returns to headquarters or a substation, a formal report must be made for evidentiary purposes. Usually, for the proper completion of modern accident reports, accurate and detailed diagrams of accident scenes must be provided by an investigating officer. Usually, drawings of accident scenes are made mechanically, with rulers, compasses, protractors, and/or prior art templates. These formal drawings must be accurate and concise, as they will often constitute important evidence that will likely be relevant to both criminal; and/or civil proceedings.
A variety of factors such as weather and road conditions, driver condition, vehicle speed and direction must be evaluated for accurate accident investigation. In collision investigation it is imperative that the point of impact and final rest position of any vehicles involved be recorded accurately. The xe2x80x9cpoint of impactxe2x80x9d is often defined as the place where a first xe2x80x9ctraffic unitxe2x80x9d makes inappropriate contact with one or more other xe2x80x9ctraffic unitsxe2x80x9d or another object, or where the first traffic unit overturns. Traffic units include automobiles, motorcycles, trucks, bicycles, or the like operating within or upon roadways. The rest position of colliding vehicles, for example, can be utilized in conjunction with measurements of skid marks to estimate vehicular speed through the point of impact to the final rest position. Quantitative measurements of skid mark lengths, and intersection dimensions are important. After an accident, the rest position of colliding vehicles provides important evidence. Skid marks at the scene must be measured, and the dimensions of the road or intersection at which the accident occurred must be determined and sketched first hand. Some important evidentiary factors, such as the starting and ending points of critical skid marks, may be marked with nails and/or paint on the highway surface for possible later use in detailed investigations, such as those involving injury accidents or fatalities. Recorded information must be accurate and verifiable for later use. Formal procedures dictate that data integrity is ensured. Once accurate data is accumulated, principles of mathematics and physics may be used with the date to calculate a variety of important parameters.
Although such data is important, time is at a premium at accident sites. The natural inclination is to clear and clean the area of debris, and to move or tow the colliding vehicles to out-of-the way positions. This xe2x80x9cclean-upxe2x80x9d must be performed efficiently, and quickly if possible, so that the normal flow of traffic is restored. Usually the investigating police officer will make a formal written report relatively soon after an accident, depending upon his or her schedule and other professional obligations. The notes and sketches prepared at the scene are then used to make more detailed, and hopefully more accurate reports and drawings. Such formal documents, if properly and accurately made, provide an excellent basis for meaningful post-accident reconstruction. With prior art system, accident scenes can be drawn with better clarity and accuracy than mere sketches. However, it is important to establish a proper scale of the scene, so that a record of critical measurements and dimensions can be preserved for later evaluation.
Original sketches made at the accident scene, when combined with measurements and other data, can be converted to relatively accurate drawings for the required reports. However, it has hitherto been time consuming and vexatious to prepare properly scaled and dimensioned drawings of complicated roadway features. For example, the proper drawing of intersections can be time consuming and challenging. Where streets or boulevards of varying dimensions and characteristics interest, it is difficult to properly draw the accident scene. Unless the drawing is proportioned or scaled properly, such that the rest position of colliding vehicles is accurately portrayed, opinions extrapolated from the data can be suspect. Complex intersections may involve odd numbers of traffic lanes, varying dimensions between intersection roads, and a variety of other structural or topographical variations.
An important goal is to properly determine and draw the relative widths of adjoining and intersecting traffic lanes. Most intersections form right angles, and so the accurate drawing of such scenes requires a xe2x80x9csquarexe2x80x9d presentation. At the same time, the intersecting lanes must be properly scaled, so that accuracy is insured when the drawing is later relied-upon for evidence.
This invention provides an efficient and accurate template for diagramming traffic intersections and accident scenes. Diagrams of intersections made with the disclosed template preserve critical proportions, as scaling is facilitated. Moreover, the proper xe2x80x9csquarexe2x80x9d geometrical relationship between intersecting streets or roads diagrammed by the template is maintained. As a result, accurate police records of accident scenes may be quickly and efficiently compiled by investigating officers. These diagrams may be drawn in either a primary scale wherein one inch equals twenty feet, or a secondary scale wherein one inch equals forty feet.
Preferably the template is made of a translucent, plastic material. Vinyl or polycarbonate plastic materials are excellent. Importantly, the template is generally L-shaped. It comprises a square midsection that is integral with a pair of outwardly projecting, perpendicularly-oriented legs. Each leg is substantially square as well. Numerous properly-shaped xe2x80x9cvoidsxe2x80x9d or cutouts in the form of various symbols and shapes readily facilitate the drawing of vehicles, trafficway control devices, topographical features, and other important details.
Calibrated inner edges of the template determine proper intersection and curbline dimensions. Besides calibrated edges, each template comprises linear, calibrated drawing slots that facilitate the scaled diagramming of reference points that establish critical roadway and lane dimensions. Each leg has a pair of these critical, internal drawing slots. The xe2x80x9cdimensioningxe2x80x9d slots are spaced furthest from the midsection, and are used to dimension a roadway and then mark its lanes. Critical xe2x80x9cprojectionxe2x80x9d slots are parallel to and spaced apart from the dimensioning slots. The projection slots are positioned closer to the template midsection, parallel with and spaced apart from the dimensioning slots. Further, the projection slots are axially aligned with critical external edges of the template to facilitate drawing of critical projection points along an intersecting roadway to later complete a properly xe2x80x9csquaredxe2x80x9d curbline.
The template further comprises a number of calibrated edges that facilitate the scaling of drawing features. These slots can provide correct scaling where dimensions are important. The template external and internal corners are curved differently to draw arcs of varying curvatures.
Calibrated inner edges of the template determine proper intersection and curbline dimensions. Besides calibrated edges, each template leg comprises a pair of linear, calibrated drawing slots that facilitate the drawing of reference points that establish critical roadway and lane dimensions, and enable the rapid subsequent drawing of curblines. A first straight drawing slot in each leg extends perpendicularly across it. These slots initially dimension a road as a curbline is drawn. A second calibrated slot parallel with the first slot is located towards the innermost portion of the template. These inner slots are collinear with critical edges of the template to preserve the resultant xe2x80x9csquarenessxe2x80x9d of the intersection and curblines drawn.
Thus a basic object is to facilitate the production of accurate accident diagrams.
A related object is to provide a drawing template that aids in the accurate diagramming of intersections and accident scenes.
Another object is to provide a drawing template that is adapted for use in drawing intersections.
A related object is to provide a template of the character describe that makes accurate, scaled drawings.
Another important object is to enable police records to accurately reflect the shape of intersections portrayed in accident investigations. It is a feature of my invention that the proposed template inherently yields drawings of the proper xe2x80x9csquareness.xe2x80x9d
Another basic object is to provide a drawing template of the character described that enables the accurate drawing of intersects, including the adjoining curblines.
A related object is to provide a template that facilitates the drawing of a variety of arcs or curves.
These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections.